Madonna, seen here with Michael at the 1991 Oscars ceremony, said she had not been able to stop crying since hearing of his death. "The world has lost one of its greats but his music will live on forever," she assured fans

Britney - who joined Michael on stage in 2001 - told how she'd looked forward to seeing him perform again. "He has been an inspiration throughout my entire life and I'm devastated he's gone," she said

From the most humble fans to giants of the music world like Madonna and Quincy Jones, admirers the world over are struggling to contain their grief for the superstar who came to be known as the king of pop.

His elder brother Jermaine Jackson announced that the Thriller artist had passed away on Thursday June 25 at 2.26pm in Los Angeles of a suspected cardiac arrest.

Shortly after hearing of his death, Madonna described how she was unable to "stop crying over the sad news".

"I've always admired Michael Jackson - the world has lost one of its greats but his music will live on forever. My heart goes out to his three children and other members of his family. God bless," she added.

In recent years the 50-year-old had become less prominent in public life, with reports about him concentrating on his ill-health and financial problems.

Nothing, however, could over shadow the respect and adoration he inspired for a prodigious talent that was evident from his earliest years.

After leaving his family group The Jackson 5, which he joined aged six, he went on to achieve global fame with hits like Billie Jean and Bad.

Such was the glitter of his career, which was littered with Grammys – 13 in all – that even the most successful talents recognised him as a cut above the rest.

Princess of pop Britney Spears, currently touring with her 'Circus' show, told how she'd looked forward to seeing him performing again.

"We were going to be on tour in Europe at the same time and I was going to fly in to see him," said the 27-year-old. "He has been an inspiration throughout my entire life and I'm devastated he's gone."

Another songbird Celine Dion spoke of her shock, hailing him "a genius". "I am overwhelmed by this tragedy. Michael Jackson has been an idol for me all my life," she said.

Cher remembered the start of his career as a child prodigy. "God gives you certain gifts and this child was just an extraordinary child touched by this ability. He could sing like nobody else and he was able to connect with people," she said.

Meanwhile Quincy, the music producer behind many of his hits, told reporters he had "lost a little brother". His ex-wife Lisa Marie Presley's reaction was one of "heartbreak for his children, who I know were everything to him".

Referring to his much-anticipated comeback in July Rev Al Sharpton - a friend of over 35 years who Michael often turned to in his darkest hours - summed up the sense of loss, saying: " We thought we'd see him moonwalk one more time".